Common Problems & Solutions in Paper Cup Production

1. Leakage at the cup bottom

    

   Cause: Insufficient bottom heating temperature, insufficient sealing pressure, uneven glue application on the bottom

    

   Solution: Increase bottom heating temperature; raise the pressure of the bottom sealing cylinder; adjust the gap and speed of the bottom glue applicator
    
2. Cup body seam cracking or debonding

    

   Cause: Improper hot air temperature, insufficient hot air pressure, paper feeding deviation, uneven heating of PE coating

    

   Solution: Adjust hot air temperature and air volume; calibrate the cup body forming guide; clean and check the hot air nozzles
    
3. Deformed or loose cup rim

    

   Cause: Worn curling rollers, insufficient curling pressure, insufficient rim heating, unsuitable paper stiffness

    

   Solution: Replace worn curling rollers; adjust the pressure of the curling mechanism; properly increase the rim heating temperature
    
4. Inconsistent cup height

    

   Cause: Inaccurate paper feeding length, worn cutting blades, servo positioning deviation, unstable paper tension

    

   Solution: Calibrate the paper feeding encoder; grind or replace cutting blades; recalibrate servo positioning parameters
    
5. Wrinkles and creases on the cup body

    

   Cause: Unsmooth paper feeding, mismatched forming molds, uneven pressure of paper guide rollers, damp paper

    

   Solution: Clean obstacles in the paper path; inspect and replace forming molds; balance the pressure of left and right paper guide rollers
    
6. Uneven gluing, glue overflow or poor adhesion

    

   Cause: Improper glue roller gap, abnormal glue concentration or temperature, worn glue scraper

    

   Solution: Fine-tune the glue roller gap; adjust glue concentration and temperature; replace the worn glue scraper
    
7. Jamming or shutdown during cup forming

    

   Cause: Glue accumulation on molds, paper path blockage, faulty sensors, excessive clearance of chains or cams

    

   Solution: Clean molds and paper path; inspect and reset photoelectric sensors; adjust the clearance of transmission parts
    
8. Out-of-round or eccentric cup bottom

    

   Cause: Eccentric bottom mold, worn bottom sealing rollers, offset bottom paper feeding, inaccurate bottom paper cutting

    

   Solution: Calibrate the concentricity of the bottom mold; replace worn bottom sealing rollers; adjust the bottom paper positioning guide
    
9. Scorching or burning marks on the outer cup wall

    

   Cause: Excessively high heating temperature, overlong heating time, misaligned hot air nozzles

    

   Solution: Reduce heating temperature; shorten heating duration; adjust the angle and position of hot air nozzles
    
10. Unstable running speed and low output

     

    Cause: Insufficient air pressure, drifted servo parameters, slipping transmission belts, unstable temperature control

     

    Solution: Check air compressor pressure; optimize servo operation parameters; tension the transmission belts